1. Field of the Invention
The present invention relates to Pseudo Wire Emulation Edge to Edge (PWE3) technology and, more particularly, to a circuit emulation method and device for transmitting time division multiplexing (TDM) signals over an asynchronous network such as Ethernet™ (hereinafter, simply referred to as Ether) or packet switched network.
2. Description of the Related Art
Various circuit emulation technologies of emulating TDM circuits over an asynchronous network such as a packet network have been proposed (for example, see Japanese Patent Application Unexamined Publication No. 2008-199162 and others). Particularly, a circuit emulation service over packet switched network (CESoPSN) has been proposed in which one or more timeslots TS destined for the same TDM circuit are bundled to generate a single packet, which is then transmitted over a packet switched network in Request for Comments 5086 (Network Working Group, “Structure-Aware Time Division Multiplexed (TDM) Circuit Emulation Service over Packet Switched Network (CESoPSN)” December 2007).
However, according to CESoPSN of RFC 5086, since a packet is generated by bundling timeslots on a TDM-circuit basis, separate packets are generated even if these packets are addressed to the same destination on a packet switched network. Therefore, multiple packets having the same Ether headers are transmitted, hampering the efficient transmission of packets and the effective use of the network band. Moreover, since there is multiple-packets traffic over the packet network, jitters may easily occur due to congestion at routers and like equipment.